Remarks. 



It is easily differentiated in the herbarium from M. 

 linarii folia, both by leaves, fruits and inflorescence, and 

 Bentham no doubt saw the distinction when he was moved 

 to give it varietal rank. Mueller also regarded it as 

 specifically distinct (supra). 



M. linariifolia has thicker branchlets, larger leaves and 

 spikes, and is altogether a more robust plant in herbarium 

 specimens, although not so large a tree, judging from data 

 available. Anatomically the difference is quite pronounced 

 as shown under leaf anatomy of each in this series of papers. 



Leaf Anatomy.— A transverse section of leaf is evenly 

 divided in the long axis into three equal and parallel por- 

 tions, the median part being occupied by the spongy 

 mesophyll, and the two outer by the palisade parenchyma. 

 Through the central structure from edge to edge of the leaf 

 run the bundles, the central one being slightly larger than 

 the others. Each is more or less surrounded by a number 

 of sclerenchymatous cells, no transfusion tissue being 

 detected. A manganese compound is a prominent feature 

 in many of the cells of the spongy mesophyll, and is indicated 

 by dark patches in the sections shown. The pailisade 

 parenchyma is very solid, being sometimes three cells deep, 

 and irregularly scattered through it occur proportionately 

 large oil glands. The stomata are found on both surfaced, 

 embedded in the epidermal cells. The oil glands are fairly 

 well scattered throughout the leaf tissue, and are of a 

 lygigenons origin; the secretory cells are long and narrow 



Essential Oil.— The leaf oil of this species of Melaleuca 

 (If. triehostachya) is of considerable commercial import- 

 ance, as it is one of the richest in cineol content of any 

 known essential oil. It compares favourably in this respect 

 with the best cineol bearing Eucalyptus oils, as K. Smithii, 



